The sketch shows a ball rolling at constant velocity along a level floor. The ball rolls from the first position shown to the second in 1 second. The two positions are 1 meter apart. Discuss with your partner where you would sketch the ball at successive 1-second intervals all the way to the wall (neglect resistance).

Would the successive ball positions be evenly spaced, farther apart, or closer together?

Why?

The ball reaches the wall with a speed of ____ m/s and takes a time of ____ seconds.

The table given below shows data of sprinting speeds of some animals. Make whatever computations are necessary to complete the table.

A =

B =

C =

animal

distance

time

speed

cheetah

75 m

3 sec

25 m/sec

greyhound

160 m

10 sec

C

gazelle

1 km

B

100 km/hr

turtle

A

30 sec

1 cm/sec

Accelerated Motion

Refer to the following information for the next eight questions.

An object, starting from rest, gains a speed v = at when it undergoes uniform acceleration. The distance it covers is d = ½at2. Uniform acceleration occurs for a ball rolling down an inclined plane. The plane below is tilted so a ball picks up a speed of 2 m/s each second; then its acceleration a 2 m/s2. The positions of the ball are shown for 1-second intervals. Fill in the blanks for total distance traveled, Δdistance traveled each second, and the final speed at the end of each interval.

D =

E =

F =

G =

H =

I =

J =

K =

cumulative time
(seconds)

cumulative distance traveled

Δdistance
per second

final speed

0

0 meters

---

0 m/sec

1

1 meter

1 meter

2 m/sec

2

4 meters

3 meters

I

3

D

F

6 m/sec

4

E

G

J

5

25 meters

H

K

Do you see that the total distance from the starting point increases as the square of the time? This was discovered by Galileo. If the incline were to continue, predict the ball's distance from the starting point for the next 3 seconds.

Note the increase of distance between ball positions with time. Do you see an odd-integer pattern (also discovered by Galileo) for this increase? If the incline were to continue, predict the successive distances between ball positions for the next 3 seconds.